Taming of transposable elements by homology-dependent gene silencing

被引:174
作者
Jensen, S [1 ]
Gassama, MP [1 ]
Heidmann, T [1 ]
机构
[1] Inst Gustave Roussy, CNRS, UMR 1537, Unite Retrovir Endogen & Elem Retroid Eucaryot, F-94805 Villejuif, France
关键词
D O I
10.1038/5997
中图分类号
Q3 [遗传学];
学科分类号
071007 ; 090102 ;
摘要
Transposable elements can invade virgin genomes within a few generations, after which the elements are 'tamed' and retain only limited transpositional activity. Introduction of the I element, a transposon similar to mammalian LINE elements, into Drosophila melanogaster genomes devoid of such elements initially results in high-frequency transposition of the incoming transposon, high mutation rate, chromosomal nondisjunction and female sterility, a syndrome referred to as hybrid dysgenesis' (for review, see refs 2-4); a related syndrome has also been described in mammals(5). High-frequency transposition is transient, as the number of I elements reaches a finite value and transposition ceases after approximately ten generations(6,7). It has been proposed that the I elements encode a factor that negatively regulates their own transcription, but evidence for such a mechanism is lacking(8). Using the hybrid dysgenesis syndrome in Drosophila(1-4) as a model, we show here that transpositional activity of the I element can be repressed by prior introduction of transgenes expressing a small internal region of the I element. This autoregulation presents features characteristic of homology-dependent gene silencing, a process known as cosuppression(9-15) Repression does not require any translatable sequence, its severity correlates with transgene copy number and it develops in a generation-dependent manner via germline transmission of a silencing effector in females only. These results demonstrate that transposable elements are prone to and can be tamed by homology-dependent gene silencing, a process that may have emerged during the course of evolution as a specific defense mechanism against these elements.
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页码:209 / 212
页数:4
相关论文
共 30 条
[1]   EPIGENETIC REPEAT-INDUCED GENE SILENCING (RIGS) IN ARABIDOPSIS [J].
ASSAAD, FF ;
TUCKER, KL ;
SIGNER, ER .
PLANT MOLECULAR BIOLOGY, 1993, 22 (06) :1067-1085
[2]   RNA as a target and an initiator of post-transcriptional gene silencing in transgenic plants [J].
Baulcombe, DC .
PLANT MOLECULAR BIOLOGY, 1996, 32 (1-2) :79-88
[3]   Cosuppression comes to the animals [J].
Bingham, PM .
CELL, 1997, 90 (03) :385-387
[4]   HYBRID DYSGENESIS IN DROSOPHILA-MELANOGASTER [J].
BREGLIANO, JC ;
PICARD, G ;
BUCHETON, A ;
PELISSON, A ;
LAVIGE, JM ;
LHERITIER, P .
SCIENCE, 1980, 207 (4431) :606-611
[5]   I-TRANSPOSABLE ELEMENTS AND I-R HYBRID DYSGENESIS IN DROSOPHILA [J].
BUCHETON, A .
TRENDS IN GENETICS, 1990, 6 (01) :16-21
[6]   Copy number control of a transposable element, the I factor, a LINE-like element in Drosophila [J].
Chaboissier, MC ;
Bucheton, A ;
Finnegan, DJ .
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 1998, 95 (20) :11781-11785
[7]   A LINE-like transposable element in Drosophila, the I factor, encodes a protein with properties similar to those of retroviral nucleocapsids [J].
Dawson, A ;
Hartswood, E ;
Paterson, T ;
Finnegan, DJ .
EMBO JOURNAL, 1997, 16 (14) :4448-4455
[8]   Post-transcriptional gene silencing in plants [J].
Depicker, A ;
VanMontagu, M .
CURRENT OPINION IN CELL BIOLOGY, 1997, 9 (03) :373-382
[9]   EXPANSIONS OF TRANSGENE REPEATS CAUSE HETEROCHROMATIN FORMATION AND GENE SILENCING IN DROSOPHILA [J].
DORER, DR ;
HENIKOFF, S .
CELL, 1994, 77 (07) :993-1002
[10]  
English JJ, 1996, PLANT CELL, V8, P179, DOI 10.1105/tpc.8.2.179